°®Âþµº

In the first incident, two Palestinians were shot dead by Israeli forces after allegedly opening fire in a street in Jerusalem's Old City.

The men were alleged by passengers on an Israeli bus to have shot at them before before fleeing the scene in a vehicle.

"Police units searched for terrorists after earlier shots were fired in another Jerusalem neighbourhood," said Israeli police spokesperson Micky Rosenfeld.

No injuries from the alleged bus shooting were reported, but Israeli police sealed off the area in attempt to trap the men, sources told °®Âþµº.

A vehicle matching a given description - with two Palestinian men inside - was later spotted by Israeli police, who opened fire at the car, killing both passengers.

The Palestinian health ministry said their identities were not yet known.

Israeli police described both as 20-year-old Palestinians from the Jerusalem area.

During the shootings, a 57-year-old Palestinian was caught in the cross-fire and received life-threatening injuries.

The vehicle used by the Palestinian men was riddled with bullet holes at the scene of an attack [Getty]

The injured man, identified as Imad Abu Ali, was transferred to Hadassah Hospital and remains in a critical, the Palestinian Ma'an news agency reported.

In a separate incident, a third Palestinian man was also shot dead by Israeli forces on Wednesday after allegedly attempting to stab an Israeli soldier at a checkpoint in the occupied West Bank.

The shootings mark yet another day of bloodshed in Israel and the occupied Palestinian territories following yesterday's violence, which saw four Palestinians shot dead after allegedly carrying out separate attacks that killed an American tourist and wounded at least 12 Israelis.

Included was the killing of on Tuesday near the al-Aqsa compound, despite bearing no weapons according to eye-witnesses.

There is a state of "heightened security across Jerusalem", Israeli police spokesman confirmed on Wednesday, as forces beefed up their presence across Jerusalem and the occupied West Bank.

Israeli forces claim enhanced security measures are necessary to counter the recent spate of attacks against Israeli soldiers and police by Palestinians.

, however, have said that Israel has waged arbitrary campaigns of arrests and shootings against Palestinians.

Swedish foreign minister Margot Wallstrom called for accused of stabbings to determine whether Israeli forces were guilty of "extra-judicial killings".

At least 191 Palestinians have been killed by Israeli fire since October, 32 of them under the age of 18. Thirty Israelis and three foreign civilians have been killed in the same period.

Israel claims that a Palestinian campaign of incitement is fuelling the violence, while Palestinians say attacks are rooted in frustration stemming from nearly five decades of Israeli military occupation.